阅读说明：本技术 一种利用电化学微通道反应装置连续制备2-芳基-苯并噻吩/呋喃类化合物的方法 (Method for continuously preparing 2-aryl-benzothiophene/furan compounds by using electrochemical microchannel reaction device ) 是由 郭凯 张东 方正 蔡谨琳 刘成扣 朱宁 张锴 欧阳平凯 于 2019-11-07 设计创作，主要内容包括：本发明公开了一种利用电化学微通道反应装置连续制备2-芳基-苯并噻吩/呋喃类化合物的方法,将乙炔基苯甲硫醚/苯乙炔基苯甲醚与含碘电解质溶解在水和乙腈中制成均相溶液,然后将制得的均相溶液利用注射泵单股进样通入电化学微通道反应装置的进料口,在直流电源作用下,反应得到产物2-芳基-苯并噻吩/呋喃类化合物；电化学微通道反应装置包括阳极电极、阴极电极、电解池支架、反应槽、直流电源以及温度控制模块；反应槽位于阳极电极和阴极电极之间,并在阳极电极和阴极电极之间形成一封闭的蛇形流动路径；阳极电极和阴极电极安装在电解池支架上；阳极电极和阴极电极的一端相互连接,并与直流电源连接；温度控制模块镶嵌在电解池支架内,用于控制反应槽内液体的温度。(The invention discloses a method for continuously preparing 2-aryl-benzothiophene/furan compounds by using an electrochemical microchannel reaction device, which comprises the steps of dissolving ethynyl thioanisole/phenylethynyl anisole and iodine-containing electrolyte in water and acetonitrile to prepare homogeneous phase solution, introducing the prepared homogeneous phase solution into a feed inlet of the electrochemical microchannel reaction device by using single-strand sample injection of an injection pump, and reacting under the action of a direct current power supply to obtain a product 2-aryl-benzothiophene/furan compounds; the electrochemical microchannel reaction device comprises an anode electrode, a cathode electrode, an electrolytic cell bracket, a reaction tank, a direct current power supply and a temperature control module; the reaction tank is positioned between the anode electrode and the cathode electrode, and a closed serpentine flow path is formed between the anode electrode and the cathode electrode; the anode electrode and the cathode electrode are arranged on the electrolytic cell bracket; one ends of the anode electrode and the cathode electrode are mutually connected and are connected with a direct current power supply; the temperature control module is embedded in the electrolytic cell bracket and is used for controlling the temperature of liquid in the reaction tank.)

1. A method for continuously preparing 2-aryl-benzothiophene compounds by using an electrochemical microchannel reaction device is characterized in that ethynyl methyl sulfide and iodine-containing electrolyte are dissolved in water and acetonitrile to prepare homogeneous solution, then the prepared homogeneous solution is introduced into a feed inlet of the electrochemical microchannel reaction device by single-strand sample injection of a syringe pump, and the product 2-aryl-benzothiophene compounds are obtained by reaction under the action of a direct current power supply;

the electrochemical microchannel reaction device comprises an anode electrode, a cathode electrode, an electrolytic cell bracket, a reaction tank, a direct current power supply and a temperature control module; the reaction tank is positioned between the anode electrode and the cathode electrode, and a closed serpentine flow path is formed between the anode electrode and the cathode electrode; the anode electrode and the cathode electrode are arranged on the electrolytic cell bracket; one ends of the anode electrode and the cathode electrode are mutually connected and are connected with a direct current power supply; the temperature control module is embedded in the electrolytic cell bracket and is used for controlling the temperature of liquid in the reaction tank.

2. A method for continuously preparing 2-aryl-benzofuran compounds by using an electrochemical microchannel reaction device is characterized in that phenylethynyl anisole and iodine-containing electrolyte are dissolved in water and acetonitrile to prepare homogeneous solution, then the prepared homogeneous solution is introduced into a feed inlet of the electrochemical microchannel reaction device by single-strand sample injection of a syringe pump, and the 2-aryl-benzofuran compounds are obtained by reaction under the action of a direct current power supply;

the electrochemical microchannel reaction device comprises an anode electrode, a cathode electrode, an electrolytic cell bracket, a reaction tank, a direct current power supply and a temperature control module; the reaction tank is positioned between the anode electrode and the cathode electrode, and a closed serpentine flow path is formed between the anode electrode and the cathode electrode; the anode electrode and the cathode electrode are arranged on the electrolytic cell bracket; one ends of the anode electrode and the cathode electrode are mutually connected and are connected with a direct current power supply; the temperature control module is embedded in the electrolytic cell bracket and is used for controlling the temperature of liquid in the reaction tank.

3. The method according to claim 1 or 2, wherein the ethynyl thioanisole is any one of 2-phenylethynyl thioanisole, 2- (3-methylphenylethynyl) thioanisole, 2- (4-fluorophenylethynyl) thioanisole, 2- (4-chlorophenylethynyl) thioanisole, 2- (4-ethylphenylethynyl) thioanisole, 2- (3-thiophene) ethynyl thioanisole, 2- (cyclopropylethynyl) thioanisole;

the phenylethynyl anisole is 2-phenylethynyl anisole or 2- (3-methylacetylenyl) anisole;

the iodine-containing electrolyte is KI, NaI and Bu₄NI or Et₄NI。

4. The method according to claim 3, wherein the molar ratio of the ethynyl thioanisole or the phenylethynyl anisole to the iodine-containing electrolyte is 1: 1-1: 3; the concentration of the ethynyl thioanisole or the phenylethynyl anisole in the homogeneous solution is 0.02-0.05 mmol/ml.

5. The method according to claim 1 or 2, wherein the volume ratio of acetonitrile to water is 3-6: 1.

6. The method according to claim 1 or 2, wherein the flow rate of the single feed of the homogeneous solution is 0.01-0.05 ml/min.

7. The method of claim 1 or 2, wherein the anode electrode is a carbon or platinum sheet; the cathode electrode is plated with platinum-titanium alloy.

8. The method of claim 1 or 2, wherein the reaction tank is made of polytetrafluoroethylene and has a volume of 0.05 to 1.0 ml.

9. The method according to claim 1 or 2, wherein the anode electrode and the cathode electrode are fixed by screws made of polytetrafluoroethylene.

10. The method of claim 1 or 2, wherein the dc power supply has a specification of 5A, 30V; the current of the reaction flow acting in the micro-channel is controlled to be 15-50 mA.

Technical Field

The invention belongs to the field of chemical synthesis, and particularly relates to a method for continuously preparing 2-aryl-benzothiophene/furan compounds by using an electrochemical microchannel reaction device.

Background

2-phenyl-benzothiophene and derivatives thereof are sulfur-containing heterocyclic compounds widely existing in nature, are important organic synthesis intermediates, are widely used for synthesizing functional materials such as medicines, pesticides and semiconductors, and are generally concerned by people. At present, the main route for preparing 2-aryl-benzothiophene compounds comprises 3 routes, (1) 2-position arylation reaction of benzothiophene; (2) coupling reaction of 2-boratobenzothiophene with an aryl donor; (3) prepared by intramolecular cyclization reaction of substituted benzene derivatives.

The 2-aryl-benzofuran compound and derivatives thereof widely exist in natural and non-natural products, and are compounds with strong biological activity, such as antifungal activity, antiviral activity, antitumor activity, antioxidation, platelet aggregation resistance, antimalarial activity, adenosine A1 receptor antagonist and the like. At present, the main synthetic routes for preparation are the traditional synthetic methods and transition metal catalysis methods.

However, in these methods, some reagents that are not very environmentally friendly are used. Therefore, it would be of great value to develop a practical, efficient and environmentally friendly method for synthesizing such compounds.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for continuously preparing 2-aryl-benzothiophene/furan compounds by using an electrochemical microchannel reaction device, so as to solve the problems of environmental pollution, high design requirement on a reactor, poor selectivity, high energy consumption and the like in the prior art.

In order to achieve the above-mentioned problem, the technical solution adopted by the present invention is as follows:

a method for continuously preparing 2-aryl-benzothiophene compounds by using an electrochemical microchannel reaction device comprises the steps of dissolving ethynyl methyl sulfide and iodine-containing electrolyte in water and acetonitrile to prepare a homogeneous solution, introducing the prepared homogeneous solution into a feed inlet of the electrochemical microchannel reaction device by single-strand sample injection of an injection pump, and reacting under the action of a direct-current power supply to obtain a product 2-aryl-benzothiophene compound;

the electrochemical microchannel reaction device comprises an anode electrode, a cathode electrode, an electrolytic cell bracket, a reaction tank, a direct current power supply and a temperature control module; the reaction tank is positioned between the anode electrode and the cathode electrode, and a closed serpentine flow path is formed between the anode electrode and the cathode electrode; the anode electrode and the cathode electrode are arranged on the electrolytic cell bracket; one ends of the anode electrode and the cathode electrode are mutually connected and are connected with a direct current power supply; the temperature control module is embedded in the electrolytic cell bracket and is used for controlling the temperature of liquid in the reaction tank.

A method for continuously preparing 2-aryl-benzofuran compounds by using an electrochemical microchannel reaction device is characterized in that phenylethynyl anisole and iodine-containing electrolyte are dissolved in water and acetonitrile to prepare homogeneous solution, then the prepared homogeneous solution is introduced into a feed inlet of the electrochemical microchannel reaction device by single-strand sample injection of a syringe pump, and the 2-aryl-benzofuran compounds are obtained by reaction under the action of a direct current power supply;

the electrochemical microchannel reaction device comprises an anode electrode, a cathode electrode, an electrolytic cell bracket, a reaction tank, a direct current power supply and a temperature control module; the reaction tank is positioned between the anode electrode and the cathode electrode, and a closed serpentine flow path is formed between the anode electrode and the cathode electrode; the anode electrode and the cathode electrode are arranged on the electrolytic cell bracket; one ends of the anode electrode and the cathode electrode are mutually connected and are connected with a direct current power supply; the temperature control module is embedded in the electrolytic cell bracket and is used for controlling the temperature of liquid in the reaction tank.

Specifically, the ethynyl thioanisole is any one of 2-phenylethynyl thioanisole, 2- (3-methylphenylethynyl) thioanisole, 2- (4-fluorophenylethynyl) thioanisole, 2- (4-chlorophenylethynyl) thioanisole, 2- (4-ethylphenylethynyl) thioanisole, 2- (3-thiophene) ethynyl thioanisole and 2- (cyclopropylethynyl) thioanisole;

the phenylethynyl anisole is 2-phenylethynyl anisole or 2- (3-methylacetylenyl) anisole;

the iodine-containing electrolyte is KI, NaI and Bu₄NI or Et₄NI。

Specifically, the molar ratio of the ethynyl thioanisole or the phenylethynyl anisole to the iodine-containing electrolyte is 1: 1-1: 3, and the preferred molar ratio is 1: 1. The concentration of the ethynyl thioanisole or the phenylethynyl anisole in the homogeneous solution is 0.02-0.05 mmol/ml.

Specifically, the volume ratio of the acetonitrile to the water is 3-6: 1, and preferably 5: 1.

Specifically, the flow rate of single-strand sample injection of the homogeneous solution is 0.01-0.05 ml/min, and the preferable flow rate is 0.02 ml/min.

Specifically, the anode electrode is a carbon sheet or a platinum sheet; the cathode electrode is plated with platinum-titanium alloy.

Specifically, the reaction tank is made of polytetrafluoroethylene, and the volume of the reaction tank is 0.05-1.0 ml, and the optimal volume is 0.5 ml.

Specifically, the iodine-containing electrolyte is KI, NaI and Bu₄NI or Et₄NI, preferably KI.

Specifically, the anode electrode and the cathode electrode are fixed through a screw, and the screw is made of polytetrafluoroethylene.

Specifically, the specification of the direct current power supply is 5A, 30V; the current of the reaction flow acting in the micro-channel is controlled to be 15-50 mA, the preferred current for preparing the 2-aryl-benzothiophene compounds is 20mA, and the preferred current for preparing the 2-aryl-benzofuran compounds is 45 mA.

Flow chemistry has been strongly driven by the advent of continuous micro-processing technology, which is likely to exceed batch processing limits. Continuous flow systems provide short diffusion paths by increasing the contact area, improve quality and heat transfer rates, and result in higher yields and more uniform particle distribution compared to conventional batch reactors.

Has the advantages that:

compared with the prior art, (1) the invention utilizes green electrooxidation to synthesize the 2-aryl-benzothiophene/furan compound with high efficiency and high selectivity by a continuous flow technology; compared with the common reaction, the reaction is green, environment-friendly and efficient; (2) compared with the common reaction time, the method for continuously preparing the 2-aryl-benzothiophene/furan compounds by using the electrochemical micro-reaction device has the advantages of shortened reaction time, improved reaction yield, stable product, easy operation, low reaction temperature, high safety, continuous and uninterrupted production, capability of effectively overcoming the defects of the traditional reaction kettle and good industrial application prospect. (3) The yield of the 2-aryl-benzothiophene compound reaches up to 96.2 percent, and the yield of the 2-aryl-benzofuran compound reaches up to 94.7 percent.

Drawings

The foregoing and/or other advantages of the invention will become further apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic view of an electrochemical microchannel reaction apparatus and a preparation process thereof.

FIG. 2 is a photograph showing a reaction vessel in the electrochemical microchannel reactor of the present invention.

FIG. 3 is a NMR spectrum of 2-phenyl-benzothiophene prepared in example 1.

FIG. 4 is a NMR carbon spectrum of 2-phenyl-benzothiophene prepared in example 1.

FIG. 5 is a NMR spectrum of 2-phenyl-benzofuran prepared in example 17.

FIG. 6 is a NMR carbon spectrum of 2-phenyl-benzofuran prepared in example 17.

Detailed Description

The invention will be better understood from the following examples.

The structures, proportions, and dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the skilled in the art. In addition, the terms "upper", "lower", "front", "rear" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the relative positions may be changed or adjusted without substantial technical changes.